Methods and apparatus for blocking flow through blood vessels

ABSTRACT

This invention is methods and apparatus for occluding blood flow within a blood vessel ( 22 ). In a first series of embodiments, the present invention comprises a plurality of embolic devices ( 16 ) deployable through the lumen ( 12 ) of a conventional catheter ( 10 ) such that when deployed, said embolic devices ( 16 ) remain resident and occlude blood flow at a specific site within the lumen of the blood vessel ( 22 ). Such embolic devices ( 16 ) comprise either mechanical embolic devices that become embedded within or compress against the lumen of the vessel or chemical vaso occlusive agents that seal off blood flow at a given site. A second embodiment of the present invention comprises utilization of a vacuum/cauterizing device capable of sucking in the lumen of the vessel about the device to maintain the vessel in a closed condition where there is then applied a sufficient amount of energy to cause the tissue collapsed about the device to denature into a closure. In a third series of embodiments, the present invention comprises the combination of an embolization facilitator coupled with the application of an energy force to form an intraluminal closure at a specified site within a vessel.

RELATED APPLICATIONS

This patent application claims priority to U.S. Provisional PatentApplication Ser. No. 60/010,614, filed on Feb. 2, 1996, and is acontinuation-in-part of U.S. patent application Ser. No. 08/730,327,filed on Oct. 11, 1996 now U.S. Pat. No. 6,190,353 and Ser. No.08/730,496, filed on Oct. 11, 1996, now U.S. Pat. No. 5,830,222, theentire disclosure of each such related application being expresslyincorporated herein by reference.

FIELD OF THE INVENTION

The present invention relates generally to medical devices, and moreparticularly to methods and apparatus for blocking or closing the lumensof blood vessels or other anatomical conduits.

BACKGROUND OF THE INVENTION

In modern medical practice, it is often desirable to block or otherwiseprevent flow through the lumen of a blood vessel or other anatomicalconduit. Examples of medical procedures wherein it is desirable to blockthe lumens of blood vessels include: a) procedures intended to diminishor block the flow of blood into vascular aneurysms (e.g., cerebralaneurysms); b) procedures intended to occlude the side branches whichemanate from a segment of a peripheral vein to prepare the vein segmentfor use as an in situ bypass conduit; c) procedures intended to treatvaricose veins; d) transvascular, catheter-based procedures forbypassing obstructed, diseased or injured arteries as described in U.S.patent application Ser. Nos. 08/730,327 and 08/730,496; e) proceduresintended to block or diminish blood flow to a tumor; f) proceduresintended to close congenital or acquired arterio-venous malformations;and g) procedures intended to temporarily or permanently block bloodflow through a vessel as an adjuvant to placement of an endovasculargraft for treatment of an aneurysm or other therapeutic intervention.

Examples of embolization devices useable to block the lumens of someblood vessels have been described in the following U.S. Pat. No.:5,382,260 to Dormandy, Jr. et al; U.S. Pat. No. 5,342,394 to Matsuno etal.; U.S. Pat. No. 5,108,407 to Geremia et al.; and U.S. Pat. No.4,994,069 to Ritchart et al.; U.S. Pat. No. 5,382,261 to Palmaz; U.S.Pat. No. 5,486,193 to Bourne et al.; U.S. Pat. No. 5,499,995 toTeirstein; U.S. Pat. No. 5,578,074 to Mirigian; and also in PatentCooperation Treaty International Publication No. WO96/00034 to Palermo.

The new transvascular catheter-based bypass procedures described inco-pending application Ser. Nos. 08/730,327 and 08/730,496 includecertain coronary artery bypass procedures wherein a tissue-penetratingcatheter is advanced, transluminally, into the coronary vasculature andis utilized to form at least one blood flow passageway (e.g., a puncturetract or interstitial tunnel) between an obstructed coronary artery andan adjacent coronary vein, at a site upstream of the arterialobstruction. Arterial blood will then flow from the obstructed coronaryartery into the adjacent coronary vein. The lumen of the coronary veinis blocked or closed off immediately proximal to the first blood flowpassageway such that arterial blood which enters the vein will be forcedto flow through the vein in the retrograde direction. In this manner,the arterial blood from the obstructed artery may retroprofuse themyocardium through the coronary vein. Or, optionally, one or moresecondary blood flow passageways (e.g., puncture tracts or interstitialtunnels) may be formed between the coronary vein into which the arterialblood has been shunted, and the obstructed artery or another coronaryartery, to allow the arterial blood to re-enter the coronary arterialtree after having bypassed the arterial obstruction. In cases whereinsuch secondary blood flow passageways are formed between the coronaryvein and one or more adjacent arteries, the lumen of the coronary veinmay be blocked or closed off distal to such secondary passageways, tofacilitate the re-entry of the shunted arterial blood into the coronaryarterial circulation. These transvascular, catheter-based coronaryartery bypass procedures present unique and heretofore unaddressedproblems relating to the type(s) of blocking apparatus which may beutilized to block the lumen of the coronary vein proximal and/or distalto the arterial-venous blood flow passageways (e.g., puncture tracts orinterstitial tunnels) formed during the procedure. In particular, whenarterial blood is bypassed through a proximal segment of the GreatCardiac Vein, it will typically be desirable to block the lumen of theGreat Cardiac Vein at or near its confluence from the coronary venoussinus. This proximal segment of the Great Cardiac Vein is of tapered orangular configuration and, as a result, the deployment of typicalembolization coils of the type traditionally utilized to embolize orblock the lumens of blood vessels or the defined spaces of aneurysm maybe inappropriate, due to the fact that such embolization coils maybecome dislodged or work loose due to the gradually tapered or wideninganatomy of- the proximal segment of the Great Cardiac Vein.

Accordingly, there exists a need in the art for the development of newmethods and apparatus for blocking or otherwise sealing the lumens ofblood vessels or other anatomical conduits, and which are usable intapered (i.e., widening) segments of blood vessel (e.g., the proximalend of the great cardiac vein) and/or are capable of being removedfollowing implantation and/or may be punctured or traversed followingimplantation.

SUMMARY OF THE INVENTION

The present invention provides methods and devices for blocking orclosing the lumens of blood vessels to prevent blood flow therethrough.The devices of the present invention provide certain advantages over theprior art, such as i) possible removeability following implantationand/or ii) possible puncturability or retraverseability followingimplantation and/or iii) the ability to provide substantially immediateand permanent blockage of flow through a tapered or widening region of ablood vessel lumen (e.g., the proximal portion of the great cardiacvein).

The devices of the present invention generally fall into two maincategories—i) implantable lumen-blocking devices, and ii) devices whichare useable to weld or otherwise cause the lumenal walls of the bloodvessel to constrict to a closed configuration or to constrict upon amember which has been placed within the blood vessel lumen.

Implantable Lumen Blocking Apparatus

The implantable lumen blocking apparatus of the present inventiongenerally comprise i) a blood vessel engaging portion which is operativeto anchor the apparatus to the surrounding wall of the blood vessel andii) a lumen blocking portion which is operative to prevent the flow ofblood in at least one direction, through the lumen of the blood vessel.

In accordance with the invention, these implantable lumen blockingapparatus are initially deployable in a radially compact configurationto facilitate their transluminal delivery through the vasculature (e.g.,within a delivery catheter or other delivery tool). After reaching thedesired implantation site, such lumen blocking apparatus are radiallyexpandable to an operative configuration wherein the blood vesselengaging portion of the apparatus will engage the blood vessel wall andthe lumen blocking portion of the apparatus will block the lumen of theblood vessel to prevent blood from flowing therethrough in at least onedirection.

Further in accordance with the invention, the vessel-engaging portion ofthe apparatus may comprise a structural frame of wire or other suitablematerial. The lumen-blocking portion of the apparatus may comprise amembrane, sponge, fabric panel, plug, disc or other member sized to betraversely disposed within the vessel lumen to block the flow of blood.

Still further in accordance with the invention, the vessel engagingportion of the apparatus may comprise a plurality of members whichemanate outwardly from a fulcrum point such that, when pressure isapplied against the fulcrum point, such pressure will cause theplurality of members to become outwardly biased and thus radiallyexpand, enlarge or exert outward pressure against the blood vessel wall,thereby deterring the apparatus from becoming dislodged or migratingfrom its seated position within the blood vessel.

Further in accordance with the invention, these implantablelumen-blocking apparatus may comprise radiographically visible materialto permit the lumen blocking device to be visualized radiographicallyfollowing implantation.

Still further in accordance with the invention, these implantablelumen-blocking apparatus may comprise resilient or shape memory materialwhich will self-expand from its operative configuration by its ownresilient force or by undergoing a phase transformation when exposed andwarmed to body temperature. Alternatively, such implantable lumenblocking apparatus may comprise plastically deformable material whichmay be deformed from its radially compact configuration to its operativeconfiguration by application of pressure or force. Such plasticallydeformable embodiments, may be initially mounted upon a deliverycatheter equipped with an outward pressure exerting tool (e.g., aballoon or other mechanical means) such that, after the device has beenpositioned at its desired location within a blood vessel, the pressureexerting tool may be used to plastically deform the device to itsradially expanded configuration wherein the engaging portion of thedevice will engage the vessel wall. Alternatively, some of theseapparatus may be inflatable from their radially compact configuration totheir operative configuration.

Still further in accordance with the invention, at least someembodiments of the implantable lumen blocking devices are removablefollowing implantation within the lumen of a blood vessel. The means bywhich such removal may be effected may include a connector or otherattachment, member to facilitate linkage or connection to a wire,catheter or other retraction apparatus so as to pull, retract, rescue,draw, aspirate or otherwise move the previously implanted into the lumenof the catheter or other removal vehicle to remove the apparatus fromthe body. Or, in embodiments wherein the vessel-engaging portion of theapparatus is formed of a shape memory alloy, the implanted apparatus maybe subjectable to an in situ treatment to cause it to radially contract.Such in situ treatment may comprise the infusion of a cooled liquid(such as saline) to cause the shape memory material of the apparatus totransition from one crystalline state to another with concurrent radialcontraction of the apparatus from its operative configuration to a moreradially compact configuration suitable for extraction and removal.

Still further in accordance with the invention, some embodiments of theimplantable lumen-blocking apparatus may incorporate a lumen-blockingportion which is retranversible (i.e. puncturable). In this manner, aneedle or other puncturing element may be passed through the apparatusfollowing its implantation to restore blood flow, or to gain access toportions of the blood vessel which are distal to the site at which theapparatus was implanted.

Still further in accordance with the invention, some embodiments ofthese implantable lumen-blocking apparatus may comprise a woven fabricor other tissue permeable material which will undergo cellular ingrowthor endothelialization. In these embodiments, the process of cellularingrowth or endothelialization may be exploited to enhance the anchoringof the apparatus within the blood vessel lumen and/or to improve thelong-term biocompatability of the apparatus following implantationthereof.

Lumen Welding Devices

The invention also includes apparatus for welding the lumen of a bloodvessel. In accordance with these embodiments of the invention, there areprovided intraluminally insertable devices having at least one suctionport and at least one energy-emitting region. Suction is applied throughthe suction port to cause the lumen of the blood vessel to collapse inan area adjacent the energy-emitting region of the device. Thereafter,energy is delivered from the energy-emitting region to weld, cauterizeor otherwise fuse the collapsed lumenal wall of the blood vessel,thereby closing the lumen of the blood vessel at that site as analternative to the use of emitted energy, these devices may deliver anadhesive or other chemical substance capable of adhering or chemicallyfusing the lumen of the blood vessel to form the desired closure of thelumen.

Further in accordance with this embodiment of the invention, there isprovided an intraluminally insertable device which has a balloon formedthereon, a fluid delivery port, and an energy emitting region when theballoon is inflated, the balloon will temporarily block the vessellumen. Thereafter, a flowable conductive medium (e.g., saline solution)may be introduced through the fluid delivery port and into the vessellumen adjacent the location of the energy emitting region. Energy isthen emitted such that the energy will be transmitted through thepreviously introduced conductive substance, to the wall of the bloodvessel, thereby resulting in shrinkage or contraction of the vessel wallso as to result in closure of the blood vessel lumen at that site.

Still further in accordance with this aspect of the invention, there areprovided intraluminal devices which deploy a core or embolic memberwhich as a diameter smaller than the lumenal diameter of the bloodvessel. These devices subsequently emit radiofrequency energy or otherenergy to cause the wall of the blood vessel to shrink or constrictabout the previously deployed core or embolic member. Thereafter, thedevice may be extracted, leaving the core or embolic member firmlyimplanted within the shrunken or constricted region of blood vessel,thereby closing the blood vessel at that site.

Further objects and advantages of the invention will become apparent tothose skilled in the art upon reading and understanding of the followingdetailed description of the preferred embodiments, and uponconsideration of the accompanying drawings wherein certain preferredembodiments and examples are shown.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a side view of a catheter utilized to deploy certain embolicdevices within the vasculature according to the present invention;

FIG. 2 is a partial cross-sectional view taken along lines 2—2 of FIG.1;

FIG. 3 is a partial cross-sectional longitudinal view of the catheter ofFIG. 1 being utilized to deploy the second of two (2) embolic deviceswithin a respective one of two adjacently positioned blood vesselshaving a blood flow passageway formed therebetween via two (2)anastomotic connections;

FIG. 3a is a perspective view of a jellyfish-type embolic deviceaccording to a preferred embodiment of the present invention;

FIG. 4 is a perspective view of the jellyfish-type embolic device ofFIG. 3a according to an alternative embodiment of the present invention;

FIG. 5 is a perspective view of a sinusoidal wire-type embolic deviceaccording to the preferred embodiment of the present invention;

FIG. 5a is a perspective view of the sinusoidal wire-type embolic deviceaccording to an alternative preferred embodiment of the presentinvention;

FIG. 5b is a perspective view of the sinusoidal wire-type embolic deviceaccording to an alternative preferred embodiment of the presentinvention;

FIG. 6 is a birdcage-type embolic device according to a preferredembodiment of the present invention;

FIG. 6a is a perspective view of a preferred alternative embodiment ofthe birdcage-type embolic device;

FIG. 6b is a perspective view of a preferred alternative embodiment ofthe birdcage-type embolic device;

FIG. 7 is a perspective view of an umbrella-type embolic deviceaccording to a preferred embodiment of the present invention;

FIG. 8 is a perspective view of a cup-type embolic device according to apreferred embodiment of the present invention;

FIG. 9a is a perspective view of a traversible-type embolization deviceaccording to a preferred embodiment of the present invention, saiddevice assuming a first closed position;

FIG. 9b is a perspective view of the traversible-type embolizationdevice of FIG. 9a assuming a second open position;

FIG. 10 is a perspective view of a diaphragm-type embolic deviceaccording to a preferred embodiment of the present invention;

FIG. 11 is a perspective view of a capped coil-type embolic deviceaccording to a preferred embodiment of the present invention;

FIG. 12a is a cross-sectional view of a ring embolizer-type embolicdevice according to a preferred embodiment of the present invention,said ring embolizer device assuming a first uninflated state within thelumen of a blood vessel;

FIG. 12b is a cross-sectional view of the ring embolizer-type embolicdevice of 12 a assuming a second inflated state within the lumen of theblood vessel;

FIG. 13a is a cross-sectional view of an expanding stent/sock-typeembolic device according to a preferred embodiment of the presentinvention, said expanding stent/sock assuming a first elongate positionwithin the lumen of a blood vessel;

FIG. 13b is a cross-sectional view of the expanding stent/sock of FIG.13a assuming a second inverted state causing said device to expandwithin said lumen;

FIG. 14 is a cross-sectional view of a hook embolizer-type embolicdevice according to a preferred embodiment of the present inventionseated within the lumen of a blood vessel;

FIG. 15 is a cross-sectional view of a covered spherical coil-typeembolic device according to a preferred embodiment of the presentinvention seated within the lumen of a blood vessel;

FIG. 16 is a cross-sectional view of an hourglass-type embolic deviceaccording to a preferred embodiment of the present invention seatedwithin the lumen of a blood vessel;

FIG. 17 is a cross-sectional view of a removable balloon-type embolicdevice according to a first preferred embodiment;

FIG. 18 is a cross-sectional view of a removable balloon-type embolicdevice according to a second preferred embodiment;

FIG. 19 is a cross-sectional view of a finder/spackler-type embolicdevice according to a preferred embodiment of the present inventiondisposed within the lumen of a blood vessel;

FIG. 20 is a perspective view of a three-way valve stent embolic deviceaccording to a preferred embodiment of the present invention disposedwithin the lumen of a blood vessel;

FIG. 21 is a cross-sectional view of an embolization agent beingdeployed within the lumen of a vessel according to a preferredembodiment of the present invention;

FIG. 22 is a perspective view of a system for blocking blood flow withina vessel according to a preferred embodiment of the present invention;

FIG. 23 is a perspective view of the distal end of a device for blockingblood flow within a vessel according to a preferred embodiment of thepresent invention;

FIG. 24 is a cross-sectional view of the distal end of the device ofFIG. 23 disposed within a longitudinal section of a blood vessel;

FIG. 25 is a cross-sectional view of the distal end of the device ofFIG. 23 being utilized to draw in the lumen of the vessel wall about thedistal tip of the device;

FIG. 26 is a cross-sectional view of the device of FIG. 23 beingutilized to form an intraluminal closure within the blood vessel;

FIG. 27 is a cross-sectional view of the distal end of a catheter beingutilized to deposit a mass of autologous tissue within the lumen of theblood vessel;

FIG. 28 is a cross-sectional view of a collection of conductive embolicstrands deposited within the lumen of a blood vessel with an externalelectrical ground shown to be extending therefrom;

FIG. 29a is a cross-sectional view of a textured electrode plugpositioned within the lumen of a blood vessel with an insulatedconductive guidewire extending therefrom;

FIG. 29b is a cross-sectional view of the electrode plug of FIG. 29abeing fused to the lumen of the blood vessel, said electrode plug beingcoupled to an energy source via the conductive guidewire;

FIG. 30 is a cross-sectional view of the distal end of a catheter beingutilized to infuse a conductive substance within the lumen of a bloodvessel, said distal end of the catheter having an insulated electrodeprotruding therefrom and a balloon assuming an inflated state positionedproximal said distal end; and

FIG. 30a is a cross-sectional view of a blood vessel having anintraluminal closure formed therein.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

Referring now to the drawings, and initially to FIGS. 1-21, there isshown methods and apparatus for occluding blood flow within a vessel ata desired location within the vasculature. The methods and apparatusdisclosed herein are particularly well suited for promptly, if notimmediately, occluding blood flow within a vessel having a tapered orwidening lumen, such as the great cardiac vein, where vaso-occlusion isespecially difficult. Likewise, the methods and apparatuses disclosedherein are ideally designed to be able to resist arterial-venous bloodpressure differences and fluctuations such that blood flow may beoccluded at the desired location for prolonged, if not indefinite,lengths of time.

This need to achieve vaso-occlusion especially presents itself incertain in-situ bypass procedures wherein blood flow passageways areformed between two adjacently situated blood vessels (e.g., between anobstructed coronary artery and adjacent coronary vein) to bypass adiseased, injured or obstructed segment of one blood vessel, as depictedin FIG. 3, and has been previously described in U.S. patent applicationSer. Nos. 08/730,327 and 08/730,496, the teachings of which areexpressly incorporated herein by reference. As shown, in order for theblood flow 18 to be rerouted around a diseased or obstructed segment 20of vessel 22 requires that the blood flow 18 be redirected into thevessel 22 from which the flow of blood originated. To ensure that theblood flow 18 reenters the obstructed vessel 22, or to enter some othervessel after having bypassed the obstruction, it is essential that theadjacently situated blood vessel 24 through which the flow 18 isrerouted is sufficiently vaso-occluded at a site both upstream anddownstream from the redirected blood flow 18.

While the prior art is replete with various embolization devices, suchas helical coils, balloon catheters, and the like, such embolic deviceslack features such as retrievability, retraversability and enhancedability to remain seated within the vasculature and withstandarterial-venous blood pressure differences, particularly at pointshaving a widening section of lumen, to thus avoid migration whendeployed at the site to be embolized. In this regard, such prior artembolization devices, most notable of which being helical coils andchemical embolic agents, are typically poorly sized or adapted tomaintain long term blocking at the desired widening section of lumen tobe embolized as the widening lumen, coupled with the continuousnon-uniform arterial-venous blood pressure exerted against the device,causes the same to migrate away from the position at which such deviceis deployed.

Additionally, such prior art embolic devices suffer from the drawback ofbeing ill designed to be advanced through and deployed from the lumen ofa delivery catheter. In this respect, such embolic devices mustnecessarily be compressed or otherwise reduced in size to be advancedthrough the lumen of the catheter and thereafter be capable of assumingan expanded position sufficient to occlude blood flow. Such devices,such as those described in U.S. Pat. No. 5,499,995 to Teirstein,however, either fail to achieve a sufficiently compressed state to allowfor easy deployment through the lumen of a catheter or, alternatively,once deployed through the catheter fail to assume a sufficientlyexpanded or vaso-occlusive configuration capable of not only occludingblood flow, but remaining firmly positioned within the lumen of thevessel at the site of desired deployment.

In a first series of embodiments illustrated in FIGS. 2-21 and discussedfurther herein, there is shown a multiplicity of embolic devices andembolic agents that are designed and configured to be deployed at thedesired site to be occluded within the vasculature using a conventionalcatheter 10, as shown in FIG. 1. As is well known in the art, suchcatheters 10 have a lumen 12 formed therein through which the embolicdevices disclosed herein may be deployed at the desired site. In thisregard, the embolic device 16, such as the one illustrated in FIG. 2, isloaded within the lumen 12 of the catheter and advanced therethrough viaa pusher 26, more clearly shown in FIG. 3. Once the desired site to beembolized is accessed by the distal end 14 of the catheter 10, theembolic device 16 is advanced through the lumen 12 of the distal end 14of the catheter 10 where the same remains resident.

Common to each of the embodiments disclosed herein is the advantage ofeach such device to either be more easily deployed, and moreparticularly, delivered through the lumen 12 of the catheter 10; resistdislodgment and remain more firmly positioned or seated at the desiredsite to be vaso-occluded; include means for retraversability to allowadditional procedures to be performed therethrough at a later date; orinclude means to allow such devices to be retrieved, typically through acatheter, at a later date. It is further advantageous to provide suchembolic devices that are radio opaque so that the position of suchdevices, and more particularly the placement thereof, can be determinedwith a high degree of accuracy. As will be recognized by those skilledin the art, such features provide the physician with enhancedcapabilities to achieve greater vaso-occlusion within a patient atspecific sites within the vasculature, as well as access or retrieve thesame in the future, as may be necessary in later procedures.

With respect to the first of such embolic devices, there is shown inFIGS. 2, 3 and 3 a a jellyfish-type embolic device 16 comprising acombination of a fabric, composite, braided, or polymer tip 16 a placedover a cylindrical wire structure or frame 16 b. The fabric or polymertip 16 a is preferably fabricated from a thin, stretchable material,such as either silicone, urethane, polyethylene, Teflon, nylon,Carbothane, Tecoflex, Tecothane, Tecoth, or other similar materialswell-known to those skilled in the art. The fabric or polymer tip 16 amay further be texturized or roughened to aid in endothelialization ofthe tip 16 a and further, may preferably be reinforced with fabriccomprised of polyester, nylon, Dacron, ePFTE, and the like, which may bemolded into the cap 16 a or exposed on the surface thereof.Alternatively, such reinforcement fabric may cover the entire polymercap 16 a or may be strategically located to prevent wear of such cap 16a. For example, such fabric may be utilized to stitch the cap onto thecylindrical wire structure 16 b.

The cylindrical structure 16 b is preferably fabricated from amalleable, radiopaque and biologically-compatible material, such asnickel titanium wire, tantalum, stainless steel, platinum, gold,tungsten, coated tungsten, titanium, MP35M Elgioy, platinum, as well asother alloys of these metals and the like, and is preferably formed tohave a zig-zag configuration. The cylindrical structure 16 b is furtheradditionally formed such that the structure may exist in a firstcollapsed state, as depicted in FIGS. 2 and 3, for deployment throughthe lumen 12 of a catheter 10, and assume a second expanded position, asillustrated in FIGS. 3 and 3a, once ejected from the distal end 14 ofcatheter 10 at the desired point to be embolized. As will be recognizedby those skilled in the art, by forming the cylindrical structure 16 bfrom heat expansive or superelastic material, such as Nitinol, suchembolic device 16 thus may assume a low profile for easier deliverythrough the lumen 12 of the deployment catheter 10. To further enhancethe ability of the device 16 to assume such low profile, the wirescomprising the cylindrical structure 16 b may be formed to complimentarycompress upon itself such that the diameter of the structure is greatlyreduced. Likewise, such materials advantageously allow the device 16 toassume an expanded configuration which thus facilitates vaso-occlusionwithin the vessel 24. In this respect, the device 16 is preferablyformed such that the elastic tip 16 a is only formed aroundapproximately one-half to one-third the distal end of the cylindricalportion 16 b to thus allow the free end of the cylinder 16 b to expandfully about the lumen of the vessel 24 once the same is deployed andallowed to assume the expanded configuration.

To further facilitate the ability of the cylindrical portion 16 b toadhere to the lumen of the vessel 24 when in the expanded configuration,the cylindrical structure 16 b may have bends formed thereabout to thusenhance the frictional engagement between the structure 16 b and thelumen of the vessel 24. As should be recognized, to achieve the optimalvaso-occlusive effect, the embolic device 16 should be deployed suchthat the membrane 16 a faces the head-on flow of blood 18. By facing theflow of blood 18 head-on, such blood pressure actually facilitates theability of the device 16 to remain seated within the desired site withinthe lumen of the vessel 24. In this regard, the free, uncovered portionof the cylindrical structure 16 b is not constricted or otherwiserestrained from assuming a fully expanded configuration. In fact, asillustrated in FIG. 3a, the free ends of the cylindrical structure 16 bmay be configured to bow outwardly to thus embed within the wall of thelumen at the site of vaso-occlusion.

As will be recognized, the embolization device 16, when lodged withinthe lumen 24 of a vessel in the expanded state, is oriented such thatthe elastomeric fabric or polymer tip 16 a produces a vaso-occlusivesurface that restricts blood flow through the vessel. Advantageously,however, such fabric or polymer tip 16 a further provides means forretraversibly accessing the vaso-occluded site, as may be necessary forcertain procedures performed at a later time. In this respect, acatheter, for example, may be axially advanced through the drum-likeocclusive barrier formed by the elastomeric tip 16 a without otherwisealtering the ability of the cylindrical structure 16 b to remain seatedaxially about the lumen of the vessel. Likewise, such device 16, byvirtue of the cylindrical structure 16 b being fabricated from heatconstrictive material, allows the device 16 to be easily retrievedthrough the lumen 12 of a catheter 10 by exposing the structure 16 b toreduced temperatures, which thus causes the cylindrical structure 16 bto assume a constricted configuration that enables the same to beaxially withdrawn into the lumen 12 of a catheter 10.

Referring to FIGS. 4, 5 and 6, there are shown alternative embodimentsof the jellyfish-type embolic device according to the present invention.With respect to FIG. 4, there is shown an embolic device 28 comprised ofa plurality of longitudinally extending wires 28 b collectivelyconnected at one end by a weld or an outer hypotube. The fabric orpolymer tip 28 a is placed about the distal one-third to one-half of thelongitudinally extending wires 28 b such that when deployed, theelastomeric tip 28 a radially expands to form a vaso-occlusive surface.As will be recognized, the longitudinally extending wires 28 b, byvirtue of their arrangement, are oriented to radially embed within thelumen of the vessel and actually enhance the ability of the device 28 tobecome more firmly seated at the site of vaso-occlusion as greaterpressure is exerted by the occluded blood flow on the fabric of polymertip 28 a. Additionally, it should be noted that such arrangement oflongitudinally extending wires 28 b may be easily collapsed to enablethe device 28 to be retrieved through the lumen of a catheter, ifnecessary at a later time. To enhance such retrievability, such devicemay further preferably include a ring member (not shown) formed upon theweld joining the elongate wires 28 b to thus provide means to hook thedevice and retrieve the same through the lumen of a catheter should itbe necessary to remove the device and restore blood flow through thevaso-occluded vessel.

FIG. 5 depicts yet another embodiment 30 of this first class of embolicdevices wherein the cylindrical structure 30 b comprises round wiresassuming a sinusoidal configuration. The cylindrical structure 30 b asshown is entirely covered with the elastomeric tip 30 a such that whendeployed, the cylindrical structure 30 b expands, thus causing theelastomeric tip 30 a to correspondingly expand radially about the lumenof the vessel, thus inhibiting blood flow therethrough. Advantageously,by fully covering the cylindrical structure 30 b with the elastomericcovering 30 a, there is thus achieved a maximal blocking effect withrespect to vaso-occlusion through the vessel.

In a preferred embodiment, the configuration of the wound wire 30 bdepicted in FIG. 5 may assume a zig-zag configuration 30 c, asillustrated in FIG. 5a. As illustrated, the wire structure is providedwith a continuous series of straight sections 30 d, rigidly connected atapices to form a zig-zag structure wherein, in a compressed state, thestress is stored in the straight sections 30 d of the device therebyminimizing the stress on the joints/apices and allowing for low profiledelivery.

In yet another preferred embodiment, the configuration of the wirestructure 30 b, 30 c and pictures 5 and 5 a, respectively, may beconfigured to form a frusto-conical structure 30 d, such as thatdepicted in FIG. 5b. Such embodiment is deployed such that the narrowend of the device is placed in the direction of blood flow with thewidening end thus being allowed to more fully expand, and thus impart agreater axial compressive force about the lumen of the vessel.

Referring now to FIG. 6, there is shown an alternative birdcage-typeembolization device 32 according to a preferred embodiment of thepresent invention. In this embodiment, the embolic device 32, comprisesa multiplicity of wires running longitudinally to form a cylindricalstructure 32 b, connected at both ends by a weld or an outer hypotubesuch that the central portion of the cylinder bows outwardly to form abulbous shape. The elastomeric tip 32 a is placed about a respective endof the device 32 to thus occlude blood flow once deployed within a lumenof a vessel. In variations of this embodiment, the cylindrical portion32 b may be formed such that the ends 32 c′, 32 c″ of the structure areinverted at both ends axially within the structure, as depicted in FIG.6a. Such configuration minimizes trauma to the vessel upon deploymentand thereafter. In an alternative embodiment, as shown in FIG. 6b, theembolic device may be formed such that the center portion of thestructure 32 b is compressed to form a straight section 32 d withbulbous structures 32 e′, 32 e″ being formed on opposed ends of thestructure 32 b. Advantageously, such configuration provides greaterapposition to the vessel wall due to the two (2) bulbous structures 32e, 32 e″ making contact axially about the lumen of the vessel.

With respect to FIG. 7, there is shown an umbrella-type embolic 34device according to a preferred embodiment of the present invention. Thedevice, similar to the aforementioned jellyfish-type embolic embolizers,includes a network of longitudinally extending wires 34 b surrounded byan elastic fabric or polymer cap 34 a. The wires 34 b according to thisembodiment, however, are outwardly hinged to force such wires 34 boutward to a larger diameter. As such, the device 34 easily assumes afirst collapsed position where it may be advanced through the catheterfor deployment, and, thereafter may expand into a second state wherebythe wires spring radially outward about the lumen of the vessel. Byvirtue of the orientation of the embolic device 34 within the vessel, itshould be recognized that the flow of blood toward the device 34actually facilitates the ability of the device 34 to remain seatedwithin the vessel. As an option, the device 34 may further be providedwith a grab ring to enable the device to be retrieved should it becomenecessary at a later time to remove the same.

FIG. 8 depicts a cup-type embolization device 36 according to apreferred embodiment of the present invention. Such device 36 comprisesat least two (2) self-expanding wire structures 36 a, 36 b bent atsubstantially their respective mid-points and intersecting at said bendsto preferably form approximately a 90° angle, although other angles maybe possible. The device 36 is covered with a graft or other microporousmembrane 36 c such that when deployed, the graft microporous membrane 36c facilitates and enhances the formation of a blood clot, thus occludingblood flow. As will be recognized, the self-expanding wire structures 36a, 36 b provide substantial radial force to seat the device within thevessel. Additionally, such device 36 offers the advantages of being ableto be easily compressed, to thus enabling the device to be advanced anddeployed through the lumen of a catheter. Such device 36 furtherprovides the advantage of being able to be retrieved, much like theumbrella embolic device discussed above, insofar as the intersection ofthe wire structures 36 a, 36 b provides an ideal location to hook andretrieve such device 36 through the lumen of a catheter. A catch-ring(not shown) may further be formed at the intersection of the wirestructures 36 a to provide simpler means for retrieving such device 36.

Referring now to FIGS. 9a and 9 b, there is shown a traversibleembolization device 38 according to yet another preferred embodiment ofthe present invention. The device 38 comprises a resilient spring disc36 a forming a conical blocker 38 a. The pointed end of the blockerrests in the vessel in communication with the blood flow path depictedby the letter A. To ensure that such closure is maintained, there isprovided a plurality of inwardly biased members 38 c that force thedevice 38 to assume a first closed position as depicted in FIG. 9a.Indeed, as should be recognized, the flow of blood in the direction Atoward the conical shape 38 a actually enhances and facilitates theability of the device 38 to remain seated within the vessel.

Advantageously, however, the traversible embolization device 38 iscapable of assuming a second open position whereby entry through theside of the device opposite the blood flow, depicted by the letter B,will cause an axial aperture to be formed within the device such thatblood flow may be restored or the vessel accessed if necessary.

Referring now to FIG. 10, there is depicted a diaphragm-type embolicdevice 42 according to a preferred embodiment of the present invention.Such device comprises a membrane 42 b stretched over a resilient,annular outer spring 42 a thus forming a disc with a flexible covering.The annular outer spring 42 a may preferably be comprised of shapememory alloy, such as Nitinol, that expands when heated to certaintemperatures, and more particularly, temperatures normally associatedwith the human body (i.e., approximately 98.6° F.). As will berecognized by those skilled in the art, the stretchable membrane 42 butilized to extend about the annular spring 42 a can be penetrated andcrossed, i.e., is retraversible, so that at a later time either side ofthe vaso-occluded site can be accessed, should it become necessary toaccess the same in the future.

Referring now to FIG. 11, there is shown a cap-coil embolic device 40according to another preferred embodiment of the present invention.Essentially, the device comprises a helical coil 40 a contained withinan elastomeric bag 40 b. The device 40 is capable of being compressed,thus allowing the same advanced through the lumen of the deploymentcatheter where it is then pushed out, via the pusher, at the desiredsite to be occluded. Once expelled, the coil 40 a expands axially withinthe vessel in alignment with the direction of blood flow, thus causingthe elastic material 40 b covering the respective ends of the coil toocclude blood flow. Such device 40, in addition to achieving the desiredvaso-occlusion, has the advantage of providing a retraversible axialpathway, formed by the elastomeric material stretched over therespective ends of the device 40, that may be accessed via a catheterthrough the occluded site should it be necessary at some later time toperform a procedure within the vessel on the site opposite thevaso-occlusion.

FIGS. 12a and 12 b depict a ring embolizer device 44 comprised of thecombination of a first hard cap of non-distensible material 44 a coupledwith a second inflatable occluder 44 b that is fabricated from moredistensible material. The device 44 is ejected through the distal end ofthe catheter with the occluder 44 b remaining in an uninflated state.The device is expelled from the catheter such that the occluder 44 b isaxially positioned within the direction of blood flow, depicted by theletter C, and is then inflated with a biologically compatible material,such as saline. By virtue of the force of the blood flow compressingagainst the inflated occluder 44 b, the distensible material of theoccluder 44 b is thus caused to radially expand and flare or bite intothe lumen of the vessel 46 as shown in FIG. 12b. In this respect, theoccluder 44 b, by virtue of it having a fixed surface area, providesradial compression about the lumen of the vessel 46 to thus cause thedevice 44 to remain in fixed position relative the lumen of the vessel.

Referring now to FIGS. 13a and 13 b, there is shown an expandingstent/sock embolic device 48 according to a preferred embodiment of thepresent invention. The device 48 comprises a matrix 48 a formed of abiologically compatible material, such as Nitinol, with a sock 48 bformed at the respective end thereof. The matrix 48 a is constructedsuch that it may assume a first collapsed position, thus enabling thedevice 48 to be advanced through a delivery catheter. In such collapsedstate, as illustrated in FIG. 13a, the device 48 is deployed at the siteto be occluded with sock 48 b formed at the end of the device beingexpelled in the direction of the blood flow, depicted by the letter D.Blood flows through the cylindrical structure 48 a and thus tends todecrease its length thereby causing a corresponding increase in itsdiameter, thus locking the structure 48 a in place. In this regard, thematrix comprising the cylindrical structure 48 a radially compressesabout the lumen of the vessel, thus causing it to remain resident. Asshould be recognized, the cap or sock 48 b is attached to the end of thecylinder to be oriented upstream the flow of blood, such that the cap orsock 48 b is caused to axially invert within the cylindrical structureto thus block blood flow, as depicted by the letter F. Such design ofthe device 48 advantageously prevents migration from the desired site ofvaso-occlusion as an increase in blood pressure pushing against suchdevice 48 actually enhances the ability of the device 48 to become moresecurely seated within the vessel at the site of vaso-occlusion andfurther provides means for retraversing the embolic device through thesock 48 b axially disposed within the matrix.

Referring now to FIG. 14, there is shown a hook-type embolic device 50according to the preferred embodiment of the present invention. Thedevice 50 comprises a sponge-like structure 50 a comprised of tangledwire having hooks or protrusions 50 b extending radially thereabout toembed the device 50 into the vessel wall in the downstream direction ofblood flow. By virtue of the frictional engagement between the hooks 50b with the lumen of the vessel 52, the device 50 is thus held in placeindefinitely. The device may further preferably include radiologicalmarkers or may be radiopaque.

FIG. 15 depicts yet another further preferred embodiment of a coveredspherical coil embolizer device 54 according to the present invention.Such device comprises a heat expandable coil (not shown) containedwithin an elastomeric covering 54 a, such as silicone or polyurethane.The coil is preferably fabricated from shape memory alloy such asNitinol, which becomes enlarged when warmed to body temperature.Essentially, the coil will expand radially at approximately 98.6° F. andwill compress radially about the lumen of the vessel 56 thus causing thedevice to remain resident at a specific site. As will be recognized, thecoil will be deployed through the catheter in a contracted state so thatthe device may be easily delivered to a specific site.

To further enhance the ability of the device 54 to remain resident at aspecific site within the lumen of a vessel, the coil may be designedsuch that when heat expanded, multiple ends of the coil 54 b protrudefrom the elastomeric covering 54 a which may serve to embed the device54 within the lumen of the vessel 56, thus enhancing its ability toremain resident.

Referring now to FIG. 16, there is shown an hourglass embolic device 58according to a preferred embodiment of the present invention. The device58 comprises a cylindrical tubular structure in which the diameter ofthe ends are greater than the diameter of the center of the device. Eachrespective end of the device is covered with a graft or other membrane58 c that, when positioned within the lumen of the vessel, occludesblood flow. The tubular structure is formed via a series of struts 58 aheld coupled at their mid-point 58 b, thus allowing the respective endsof the struts to radially splay out which thus exerts radial pressure atboth ends of the device, as depicted by the letter G. In an alternativeembodiment, the struts, as opposed to being held coupled at theirmid-point, are biased at their respective mid-points such that whencollectively held together form the cylindrical tubular structure shownin FIG. 16.

Advantageously, by exerting radial pressure at two points along thelength of the vessel, such device 58 achieves a greater ability toremain seated, and thus will not migrate from its desired site ofocclusion. In this regard, such device 58 actually becomes more firmlyembedded within the lumen of the vessel as greater pressure is exertedagainst the ends of the device 58. Furthermore, when the biased strutsare utilized in the aforementioned alternative embodiment, there isadditionally provided a retraversible axial pathway at the vaso-occludedsite as the struts need not be coupled at their mid-point, which wouldotherwise obstruct such axial pathway.

Furthermore, such device 58 provides the advantage of being easilydeployed, as well as retrieved, as the device 58 may easily assume acollapsed, linear configuration by lining the struts 58 a in generallyparallel relation to one another, thus reducing the size of theradially-extending ends of the struts of the device. Such reduction inthe diameter of the ends of the device 58 allows it to be easilyadvanced through or withdrawn into the lumen of a catheter.

Referring now to FIG. 17, there is shown a removable embolic device 60,according to a preferred embodiment, comprised of an inner core 60 a andan outer coating 60 b, wherein the inner core 60 a consists of amaterial that expands and contracts via controllable means, such as achemical reacting to either heat or cold, such as contacting the device60 with heated or chilled saline solution. Such expansion andcontraction of the inner core 60 a may further be controlled by the useof thermal shape memory metal, such as Nitinol, or plastic having arequisite expandable force. Such inner core 60 a may further becomprised of hydrogel contained within an elastomeric bag. As will berecognized, once the inner core 60 a is deployed and is reacted toassume an expanded state, the outer coating 60 b expands to radiallycompress about the lumen of the vessel, thus occluding blood flow. Aswill be recognized, such device 60 advantageously allows for reversiblevaso-occlusion insofar as the inner core 60 a may be constricted, andthus the embolic device removed, as may be necessary at a later time tofacilitate the removability of such device 60, outer coating 60 b maypreferably be fabricated from elastomeric materials having a smoothsurface that is resistant to ingrowth and prevents blood fromcoagulating thereabout. As will be recognized, such features enable suchdevice 60 to be more easily removed without the possibility of damagingor otherwise disrupting luminal tissue.

Similar to the embodiment depicted in FIG. 17, FIG. 18 depicts aremovable balloon embolization device 62 which comprises a balloonfilled with heat expandable material such that at temperatures above 90°F., the expandable material expands outwardly to hold the balloon infixed position relative the vessel wall. By virtue of the balloon-likenature of the outer periphery of the device, there is thus provided aless traumatic means of occluding blood flow. As with the devicedepicted in FIG. 17, the removable balloon embolization device 62 mayadvantageously be retrieved by the application of a cooling source, suchas cold saline. Likewise, to enhance such retrievability, the balloonembolization device 62 should be fabricated from stretchable materialhaving a smooth outer surface that is resistant to ingrowth and preventsblood from clotting thereabout.

Referring now to FIGS. 19 and 20, and more particularly 19, there isshown two (2) embodiments of the present invention capable ofrestricting blood flow in more than one direction, and may further beutilized to reroute the flow of blood in a given direction. With respectto the embodiment shown in FIG. 19, there is shown an embolizerfinder/spackler 64 consisting of a double balloon catheter having acentral lumen, having a plurality of apertures 64 d formed thereon,disposed therebetween and integrally formed therewith. When deployed asshown, each respective balloon 64 a, 64 b is inflated to expand aboutthe lumen of the vessel and thus occlude blood flow therethrough. Thelumen 64 c disposed between the respective balloons 64 a, 64 b may beutilized to infuse contrast media via the apertures 64 d formed thereonfor defining offshoot vessels 68 extending from the portion of theoccluded vessel 66. The lumen 64 c disposed between the balloons mayfurther be advantageously utilized to infuse embolization means to thusocclude any offshoot vessels 68 extending from the embolized section ofvessel 66.

Such embodiment, in addition to providing the desired vaso-occlusion,further provides the advantage of defining offshoot vessels 68 that mayotherwise go undetected (i.e., difficult to visualize) due to the highblood flow rate passing through the main vessel to be occluded. As willbe appreciated by those skilled in the art, such high blood flow ratehas a tendency to wash out or otherwise prevent sufficient contrastmedia from building up to detectable concentrations in such offshootvessels. Additionally, such embodiment 64 further advantageously allowsfor the infusion of embolization means while such catheter remains inplace in the vessel, thus eliminating the need for additional devicesand procedure in the event it is necessary to occlude such offshootvessels.

FIG. 20 depicts a three-valved stent 70 positionable within a vesselthat, in addition to occluding blood flow, may be advantageouslymanipulated to redirect blood flow through a vessel as may be desired.In this respect, the stent 70, which may be deployed as all of the otheraforementioned embodiments, namely, via expulsion through the lumen of acatheter of a desired location, is provided with three (3) valves 70 a,70 b, 70 c capable of occluding or facilitating blood flow. Therespective valves 70 a, 70 b, 70 c may be manipulated such that bloodflow paths can be controlled at particular pressure differentials.Advantageously, such embodiment 70 may be customized to create one flowchannel under one set of pressure conditions and a different flow pathunder different conditions.

Referring now to FIG. 21, there is shown yet a still further preferredway to achieve the desired site-specific vaso-occlusion via thedeployment of a vaso-occlusive agent 72 through the distal end of thecatheter. As will be recognized, such embolic agent 72 may be aninjectable fluid, such as a liquid polymer, that gels into a solidspace-filling mass, at the site or sites to be occluded. Alternatively,such embolic agent 72 may comprise microspheres comprised of solid orwoven material that adheres to and accumulates about the site to beoccluded. Such accumulation thus causes the blood vessel to becomeoccluded due to the generation of a blood clot about the embolic agent.To provide means for controllably releasing such embolic agent, theremay be provided a vacuum source capable of applying controlled suctionwithin the lumen 12 of the deployment catheter 10 to thus such back anyexcess embolic agent.

While it is understood that the aforementioned embolic devices disclosedherein are particularly well suited and adapted for vaso-occlusionwithin a vessel, it should further be recognized that such devices mayhave applicability to all cases where occlusion within a pathway isnecessary.

Referring now to FIGS. 22-26, there is shown a further methods andapparatus for occluding blood flow at a specific site within thevasculature. As illustrated in FIG. 22, the system 74 comprises thecombination of a suction source 76 and an energy source 78 that areconnected to and may be applied through a catheter or similar device viaa hub attachment. The suction source 76 may be any of a number ofdevices capable of generating and sustaining a suction force. The energysource 78 may comprise either an RF or a microwave generator, laser orlight source, or may just be a source of an electric current.

Referring now to FIG. 23, there is shown a preferred embodiment of thedistal end 80 of a deployment catheter utilized to occlude blood flow ata desired site according to a preferred embodiment of the system 74. Asillustrated, distal end 80 comprises a distal tip 82 having at least oneelectrode 84 formed at the distal-most end thereof designed to impartthe energy received from the energy source 78. The distal tip 82 isfurther provided with at least one aperture 86 through which the suctionforce, provided via the suction source 76, may be applied. As will berecognized, the distal end 80 preferably includes two apertures 86 a, 86b formed on opposed sides of the distal tip 82 to thus provide a uniformsuction thereabout. Proximal end 80 is preferably provided a balloon 88capable of inflating radially about the delivery catheter.

Referring now to FIGS. 24 through 26, there is schematically shown thesteps illustrating intraluminal closure of a vessel according toapplication of the system 74. As shown in FIG. 24, the catheter, andmore particularly distal end 80 thereof, is advanced through thevasculature to the desired site to be occluded. As discussed above, thedesired site to be embolized may be accessed using conventional meansknown to those skilled in the art, such as by the use of a number ofimaging modalities, such as by means of a specific image marker whichmay be disposed on distal end 80 of the catheter.

Once the desired site is accessed, the distal tip 82 of distal end 80 ispositioned just proximal the site to be occluded. The balloon 88 formedproximal end 80 is then inflated to temporarily occlude blood flow, aswell as to maintain the position of the distal tip 82 at the desiredsite where there is to be formed the intraluminal closure. Thereafter,the suction source 76 is applied such that the lumen of the vessel 90 isdrawn to and collapses about the distal tip 82 of the device, asillustrated in FIG. 25. To facilitate the adherence of the lumen 90 ofthe vessel about the distal tip 82, such distal tip 82 may preferably betapered. It should be recognized, however, that the lumen of the vesselmay be collapsed about the distal tip of the device by mechanical means,such as by a hook extendable through the distal end of the catheter,that can embed within the lumen of the vessel and bring the same intocontact with the distal end of the catheter.

While maintained in such collapsed state about the distal tip 82 ofdistal end 80, as illustrated in FIG. 26, the energy source 78 connectedto the device may be activated to transfer energy to the electrodes 84disposed on the distal tip 82. As illustrated, the electrodes 84 deliverthe energy to the junction between the apposed collapsed vessel walls90, thus causing the walls of the lumen 90 to become fused or otherwisedenatured to form a permanent closure within the lumen of the vessel. Itshould be noted that to enhance the ability of the device to morethoroughly fuse or otherwise close off the lumen of the vessel, theremay further be provided an energy absorbing substance applied to thelumen of the vessel 90 that denatures or otherwise becomes fused to thelumen of the vessel. Such energy absorbing substances may comprisesubstances such as fibrin, polymers, or collagen. Alternatively, theremay be provided a conducting substance applied to or about the lumen ofthe vessel 90, such as saline, to thus facilitate the transfer of energyfrom the electrodes 84 to the lumen of the vessel 90.

As will be recognized, the intraluminal closure formed via theaforementioned two (2) step process, namely, by collapsing the tissuewithin the lumen of the vessel and fusing the same to form an occlusivemass, forms a permanent closure within the lumen of the vessel, suchclosure may nonetheless be reopened at a later time by cutting orotherwise forming a bore through the denatured tissue mass. Indeed, itis contemplated that certain channel connectors, such as those describedin Applicant's co-pending PCT International Patent Application No.PCT/US97/01463, may be positioned within the fused tissue to thusprovide means to restore blood flow through the vessel.

Referring now to FIGS. 27 to 30 a, there is shown yet another series ofembodiments of methods and apparatus for occluding blood flow within avessel. With respect to the following class of embodiments, there isprovided the combination of an embolic facilitator coupled with theapplication of an energy force to thus fuse the embolic facilitator tothe lumen of a vessel at the specific site to be occluded. As with thefirst series of embolic device embodiments illustrated in FIGS. 2-21above, the embolic facilitator is deposited within the vasculature, viaa catheter, at the desired site to be embolized. Once positioned, thereis applied a cauterizing or denaturing energy source which thus causesthe lumen of the vessel to fuse about and fictionally adhere to theembolic device.

Referring now to FIG. 27, there is shown the first of such embodiments.The particular embodiment 92 shown comprises the use of a mass of formedautologous tissue 94 harvested from the patient, which is deposited, viaa catheter, at the site to be occluded. Thereafter, a denaturing orcauterizing energy can be applied, via an electrode disposed within thelumen of the deployment catheter, the tissue 94 to thus weld the same tothe lumen of the vessel 96. It should be recognized, however, that suchautologous tissue 94 may alternatively be wedged into place at thedesired site to be embolized without being fused to the lumen of thevessel.

Such embodiment 92 advantageously provides high biocompatability,coupled with the fact that an abundant source of such material may bereadily derived from the host patient. Furthermore, the vaso-occlusionachieved by using autologous tissue has the advantage of being easilyremoved insofar as such tissue may be readily removed at a later time bydegrading the tissue, such as by cauterizing or cutting the same, at alater date.

In an alternative embodiment, as depicted in FIG. 28, the embolicfacilitator device comprises a mass of intertwined wire mesh 100,referred to herein as embolization strands, that are connected atvarious random points within its structure and attached to an electrodeor electrodes 102 whereby such strands 100 can be sufficiently energizedto cause coagulation, and hence embolization, within the lumen of thevessel. At present, it is believed that the application from 2 to 50watts to the strands 100 is sufficient to cause the necessarycoagulation at the site to be embolized. As will be understood by thoseskilled in the art, the application of such power necessarily requiresthat an external ground plate 106 be applied to thus complete thecircuit utilized to deliver such power.

Referring now to FIGS. 29a and 29 b, there is shown yet anotherembodiment of the embolization system according to the presentinvention. Referring firstly to FIG. 29a, there is provided acylindrical, tubular electrode plug 110 having an insulatedguidewire/conductor 112 extending from the proximal end thereof. Theguidewire/conductor 112 preferably includes a breakpoint 112 a formed atthe distal end thereof, just proximal the electrode plug 110. Asdepicted in FIG. 29b, the guidewire/conductor 112 is connected, via aconnector 118, to an energy source 116, which preferably comprises an RFgenerator.

Once the site to be occluded has been accessed, RF energy is applied viathe electrode plug 110 where such energy causes the vessel 114 to shrinkabout the plug 110 due to dehydration and denaturation of the lumentissue 114, as illustrated in FIG. 29b. The plug 110 thus becomes fusedto the lumen 114 of the vessel and, as such, occludes blood flow. Afterthe plug 110 has been sufficiently fused to the lumen tissue 114, theguidewire/conductor 112 is detached from the plug 110 by causing theguidewire 112 to sever at the breakpoint 112 a formed on the distal endthereof. As will be recognized, the guidewire 112 may be configured todetach at the breakpoint 112 a by forming the wire 112 such that thesame breaks at the breakpoint 112 a when sufficient tension is appliedthereto. In this respect, it will be recognized that the tensionnecessary to break the guidewire 112 at the breakpoint 112 a will beless than the tension necessary to dislodge the plug 110 from the tissuefrom which it is fused within the lumen of the vessel. As analternative, the breakpoint 112 a may be formed to act as a fuse whichcould be broken by overloading the current of energy runningtherethrough.

Referring now to FIG. 30, there is yet another preferred embodimentaccording to the embolization method of the present invention. In thisembodiment 120, a deployment catheter 10 having an inflatable balloon128 formed just proximal the distal end thereof is advanced to a sitewithin the vasculature to be occluded. The balloon 128 is inflated to apoint sufficient to occlude blood flow, as well as fix the distal end 14of the catheter in position to form an intraluminal closure within thevessel at the desired site. In this regard, once maintained in thedesired position, via the balloon 128, a conductive substance 122, suchas saline, for example, is ejected from the distal end of the lumen ofthe catheter 14. A current is then passed through the conductivesubstance via an insulated electrode 126 extending through the distalend of the catheter 14. A current is then passed through the conductivesubstance 122 and about the lumen of the vessel 130, thus causing thelumen 130 to denature such that a closure 130 a, as depicted in 30 a, isformed. As will be recognized, deployment of the balloon 128 prior toperforming such procedure is necessary insofar as the application of anelectric current in the presence of blood or other protein-containingfluid causes the latter to denature and congeal, thus possibly causingan undesirable thrombogenic event within the patient.

There has thus been described in a plurality of methods and apparatusfor selectively occluding blood flow at a specific site or sites withinthe vasculature. While it is understood that the methods and apparatusdisclosed herein are particularly well suited for intraluminal closurewithin a blood vessel, it should be understood by persons of ordinaryskill in the art that the general method and devices as described hereinare equally applicable to all cases where tissue needs to be broughtinto apposition for the purpose of creating a bond between the tissuesurfaces. Such applications of the present invention may include, butare not limited to, closing wounds, bowel, lymphatics, ducts, gapsbetween tissues, or punctured access sites. It should be furtherunderstood that the methods and apparatus disclosed herein may beutilized to enhance drug delivery at specific sites within the body. Itis therefore understood that modifications may be made without deviatingfrom the scope of the present invention.

What is claimed is:
 1. A device which is implantable in a blood vesselto block the flow of blood in at least one direction through a lumen ofthat blood vessel, said device comprising: a) a blood vessel engagingportion comprising a cylindrical frame initially disposable in aradially collapsed configuration such that said device may be passedinto the lumen of said blood vessel, and subsequently expandable to anoperative configuration wherein the cylindrical frame will frictionallyengage a wall of the blood vessel to hold the device in a substantiallyfixed position within said blood vessel lumen, a hollow channelextending longitudinally through the cylindrical frame when thecylindrical frame is expanded to its operative configuration; and, b) alumen blocking portion comprising a flexible sock member that has anopen end and a substantially closed end, the open end of said flexiblesock member being affixed to the cylindrical frame such that when thecylindrical frame is disposed in its operative configuration within ablood vessel, blood flowing through the blood vessel will enter the sockmember and will be substantially blocked by the sock member from flowingthrough the hollow channel of the cylindrical frame.
 2. The device ofclaim 1 wherein the cylindrical frame comprises a wire matrix.
 3. Thedevice of claim 1 wherein said blood vessel engaging portion furthercomprises an inflatable member.
 4. The device of claim 1 wherein saidblood vessel engaging portion has projections which embed in the wall ofthe blood vessel.
 5. The device of claim 1 wherein said blood vesselengaging portion has hooks which embed in the blood vessel.
 6. Thedevice of claim 1 wherein said flexible sock member is a woven fabricmember.
 7. The device of claim 1 wherein said flexible sock member isformed at least partially of a material which is capable of beingpenetrated by a transluminally advanceable penetrating member, after thedevice has been implanted in a blood vessel lumen.
 8. The device ofclaim 1 wherein the blood vessel engaging portion of the device isradially contractible following implantation so as to disengage from theblood vessel wall, thereby facilitating removal of the device.
 9. Thedevice of claim 8 wherein said device further comprises a connectorformed on the device to facilitate connection of the device to atransluminally inserted retrieval instrument which is operative to pullthe device in to an adjacent catheter.
 10. The device of claim 8 whereinthe cylindrical frame portion of the device is constructed such that,when the retrieval instrument is attached to the connector and a pullingforce is applied to the retrieval instrument, the cylindrical frame willradially contract, thereby facilitating retraction of the device into anadjacent catheter.
 11. The device of claim 1 wherein the cylindricalframe is formed at least partially of a shape memory material whichtransitions to said operative configuration when warmed to bodytemperature, but which may be radially contracted in situ by bathing thedevice in a cooled liquid so as to cool the device to a shape memorytransition temperature which is lower than body temperature.
 12. Thedevice of claim 1 wherein the cylindrical frame is formed at leastpartially of resilient self-expanding material which is biased to saidoperative configuration such that, when unconstrained, the cylindricalframe will resiliently self-expand to said operative configuration. 13.The device of claim 1 wherein the cylindrical frame is formed at leastpartially of a plastically deformable material which is initially ofsaid radially compact configuration, but which is subsequentlydeformable to said operative configuration by the application ofpressure against said device.
 14. The device of claim 1 wherein saidblood vessel engaging portion comprises a radiographically visiblematerial.
 15. The device of claim 1 wherein said flexible sock membermay be selectively penetrated to permit advancement of a catheter ordevice through the hollow channel of the cylindrical frame.
 16. Thedevice of claim 1 wherein said flexible sock member comprises amembrane.
 17. The device of claim 1 wherein said membrane includes afirst side formed of a first material which is resistant to cellularingrowth, and a second side formed of a second material which issusceptible to cellular ingrowth.
 18. The device of claim 1 wherein saidflexible sock member is oriented on said frame relative to the directionof blood flow such that the hemodynamic pressure on said flexible memberwill exert force on the frame in a manner which causes the frame toexert increased outward force against the blood vessel wall.